2016 579 low voltage disconnect

If you leave the key on then you're draining the battery.

Your LVD might be defective as most are set to sound a alarm when they get under 12 Volts.

Either that or you could have some bad batteries.

 

Mine will occasionally cut off all power AFTER the APU starts and is charging the batteries, and doesn't reset and turn the power back on unless I cycle the key on and back off which sometimes shuts the APU back off...I have heard other drivers in 579's also complain about those useless POS as well. I haven't heard of a quick fix for the issue, I just deal with it. Pete's are not what they use to be in the good old days, that is for sure, I sure wouldn't own one if given the choice.

 

NO you can't adjust them, they are sealed or the adjustment is. If you own the truck, then you can bypass it all together.

 

The tone for stuff like low air warning, turn signals, the low voltage warning and my company's wingman warning tone generator is part of the lcd display screen/gauge cluster. You have to disassemble the dash to get to it, and there is a speaker on the back...but blocking one sound blocks them all.

 

Mine only does that if you leave some external current draw on, such as the clearance lights. Doesn't cut all power though, just chimes and the APU kicks off. No big deal.

 

Dealer can disable the LVD or lower the voltage that triggers it.
Buzzing noise under the hood would be the fuel pump (cummins)